Vehicle, apparatus for generating driving sound of vehicle, and apparatus and method for controlling driving sound of vehicle

ABSTRACT

Disclosed are a vehicle, an apparatus for generating a driving sound of the vehicle, and an apparatus and method for controlling a driving sound of the vehicle. The present invention intends to provide a driving sound of a vehicle having a characteristic desired by a driver. The vehicle according to an embodiment of the present invention includes: a voice signal input unit configured to receive a voice signal; a filter generation unit configured to extract a characteristic of the voice signal and generate a driving sound filter considering the characteristic of the voice signal; and a driving sound control unit configured to generate a default driving sound based on a driving state of the vehicle and generate a new driving sound obtained by applying the driving sound filter to the default driving sound.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation patent application of U.S. patentapplication Ser. No. 14/564,039, filed on Dec. 8, 2014 which claims thebenefit of priority to Korean Patent Application No. 10-2014-132362,filed on Oct. 1, 2014 in the Korean Intellectual Property Office, thedisclosures of which are incorporated herein by reference.

FIELD

Embodiments of the present invention relate to a vehicle, and moreparticularly, to a control of a driving sound of a vehicle.

BACKGROUND

Noise of a vehicle is a disturbance that distracts the concentration ofa driver and causes an indoor environment to be unpleasant. However, onthe other hand, the noise is one of the important elements, which mayprovide emotional satisfaction that allows a driver to feel dynamics ofthe vehicle and enables the driver to feel momentum and maneuverabilityof the vehicle,

Accordingly, even upon developing an electric vehicle with almost nonoise and vibration, devices configured to artificially generate andprovide an appropriate vehicle noise according to a driver's taste andpreference have been developed and presented. Furthermore, some vehicleenthusiasts invest time and money in implemeting a unique engine soundof a specific model in their vehicles and put much effort to synthesizetheir preferred sound timbre.

SUMMARY

An aspect of the present inventive concept provides a driving sound of avehicle having a characteristic desired by a driver.

In accordance with one aspect of the present invention, the vehicleincludes: a voice signal input unit configured to receive a voicesignal; a filter generation unit configured to extract a characteristicof the voice signal and generate a driving sound filter considering thecharacteristic of the voice signal; and a driving sound control unitconfigured to generate a default driving sound based on a driving stateof the vehicle and generate a new driving sound obtained by applying thedriving sound filter to the default driving sound.

The filter generation unit may include a filter synthesis unitconfigured to generate the driving sound filter using at least oneresonance frequency of the voice signal; and a filter storage unitconfigured to store the driving sound filter.

The filter synthesis unit may select the at least one resonancefrequency of the voice signal through spectral analysis of the voicesignal.

The driving sound control unit may include a driving state detectionunit configured to detect a driving state of the vehicle.

The driving state detection unit may include at least one of arevolutions-per-minute (RPM) sensor, a torque sensor, a throttleposition sensor, an accelerator position sensor, and a wheel speedsensor.

The driving sound control unit may further include a control unitconfigured to control generation of the default driving sound andgeneration of the new driving sound.

A level of the new driving sound may be adjusted by adjusting decibelsof the driving sound filter.

The voice signal input unit may be a microphone.

The microphone may be a hands-free microphone.

The microphone may be a voice control microphone for inputting a voice.

The microphone may be a microphone of a mobile communication terminal.

The driving sound filter may be a finite impulse response (FIR) filter.

The driving sound filter may be an infinite impulse response (IIR)filter.

The voice signal may be a cry of a pet.

The voice signal may be a cry of a wild animal.

In accordance with another aspect of the present invention, a drivingsound filter generation device of a vehicle includes: a filter synthesisunit configured to extract a characteristic of a voice signal from atleast one resonance frequency of the voice signal to generate a drivingsound filter; and a filter storage unit configured to store the drivingsound filter.

The filter synthesis unit may select the at least one resonancefrequency of the voice signal through spectral analysis of the voicesignal.

A level of the new driving sound may be adjusted by adjusting decibelsof the driving sound filter.

In accordance with still another aspect of the present invention, adriving sound control device of a vehicle includes: a driving statedetection unit configured to detect a driving state of the vehicle; anda control unit configured to generate a default driving sound based onthe driving state of the vehicle and generate a new driving soundobtained by applying a previously provided driving sound filter to thedefault driving sound.

The driving state detection unit may include at least one of arevolutions-per-minute (RPM) sensor, a torque sensor, a throttleposition sensor, an accelerator position sensor, and a wheel speedsensor.

A level of the new driving sound may be adjusted by adjusting decibelsof the driving sound filter.

In accordance with still another aspect of the present invention, amethod of controlling a driving sound of a vehicle, the method includes:receiving a voice signal; extracting a characteristic of the receivedvoice signal and generating a driving sound filter considering thecharacteristic of the voice signal; and generating a default drivingsound based on a driving state of the vehicle and generating a newdriving sound obtained by applying the driving sound filter to thedefault driving sound.

The driving sound filter may be generated using at least one resonancefrequency of the voice signal.

The method may further include storing the driving sound filter.

At least one resonance frequency of the voice signal may be selectedthrough spectral analysis of the voice signal.

A level of the new driving sound may be adjusted by adjusting decibelsof the driving sound filter.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the invention will become apparent andmore readily appreciated from the following description of theembodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a view showing a vehicle according to an embodiment of thepresent invention;

FIG. 2 is a block diagram showing a control system for generating adriving sound of a vehicle according to an embodiment of the presentinvention;

FIG. 3 is a block diagram showing a configuration of a driving statedetection unit as shown in FIG. 2;

FIG. 4 is a flowchart showing a method of generating a driving soundfilter in controlling a driving sound of a vehicle according to anembodiment of the present invention;

FIGS. 5A and 5B are views showing selection of a main resonancefrequency and generation of a filter through spectral analysis;

FIG. 6 is a flowchart showing a method of controlling a driving sound ofa vehicle according to an embodiment of the present invention; and

FIG. 7 is a view showing a method of generating a new driving sound bycombining a default driving sound of a vehicle and a driving soundfilter according to an embodiment of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout.

FIG. 1 is a view showing a vehicle according to an embodiment of thepresent invention. A vehicle 100 moves by rotating its wheels due todriving power generated by a driving engine 102. When the engine 102 isdriven, an engine sound is generated by the engine 102 (an arrowdepicted as a dashed line) and introduced into a passenger compartment104. The passenger compartment 104 is an area of a vehicle intended forthe seating of a driver 106. An engine sound generated by the engine 102may be different from that desired by the driver 106. The vehicle 100according to an embodiment of the present invention generates a drivingsound desired by the driver 106 through a driving sound control device110 and provides the generated driving sound to the passengercompartment 104, thus providing a driving sound satisfying a requirementof the driver 106.

In FIG. 1, a mobile terminal, designated by reference numeral 108, maybe a smartphone or table PC, a pad-type terminal, or a notebook. In thevehicle 100 according to an embodiment of the present invention, thedriver 106 may start an operation needed to generate the driving soundthrough an application running on the mobile terminal 108.Alternatively, the driver 106 may start the operation needed to generatethe driving sound by using at least one predetermined button that isprovided to the vehicle 100.

FIG. 2 is a block diagram showing a control system for generating adriving sound of a vehicle according to an embodiment of the presentinvention. As shown in FIG. 2, a control system for generating a drivingsound of a vehicle according to an embodiment of the present inventionmay include a microphone 202, a filter generation unit 210, and adriving sound control device 110.

The microphone 202 is an example of a voice signal input unit, which isused to receive a voice signal. The microphone 202 may be a hands-freemicrophone of the vehicle 100. Alternatively, the microphone 202 may bea microphone used to receive a voice signal of the driver 106 to performvoice recognition-based control of the vehicle 100. If a system for thevoice recognition-based control is provided to the vehicle 100, a devicefor analyzing a voice signal to perform voice recognition may beprovided. In this case, spectral analysis of a voice signal according toan embodiment of the present invention may be carried out using thedevice for analyzing a voice signal, without a separate voice signalanalyzer. Alternatively, the microphone 202 may be a microphone of themobile terminal 108.

A voice signal received through the microphone 202 is a human voicesignal. For example, the voice signal may be a voice of someoneincluding the driver 106. Alternatively, the voice signal is a cry of apet. A driving sound filter considering a cry of a pet (for example, adog or a cat) raised by the driver 106 may be generated by inputting thecry of the pet through the microphone 202. Alternatively, the voicesignal is a cry of a wild animal. A driving sound filter considering acry of a specific wild animal (for example, a tiger or leopard) may begenerated by acquiring the cry of the animal and inputting the acquiredsound through the microphone 202.

A sound source of a voice wave form is classified into periodicvibration of the vocal cords due to continuous opening and closing of aglottis and noisy air vibration caused by blowing air to a narrow spaceformed by a tongue, teeth, a lip, and the like in a mouth. Thevocal-cord-vibration-based sound source includes a basic vibration soundand harmonic sounds whose frequency is an integer multiple of the basicvibration sound. A basic frequency of the vocal cord vibration isinversely proportional to a length of the vocal cords, is proportionalto the square root of a tension of the vocal cord times the accelerationof gravity, and is inversely proportional the square root of a specificgravity of the vocal cords times a cross-section of the vocal cords.Vowel sounds and voiced consonant sounds are generated by resonating avocal tract in which periodic air vibration due to the vocal cords, thatis a sound source, is a resonance system. In the vocal cord vibration,each harmonic has different amplitudes, and several harmonics arestrengthened by resonance characteristics of the vocal tract. Theresonance characteristics of the vocal tract work as a filter. Thus, theharmonics are strengthened at some frequencies and weakened at otherfrequencies according to a size and a shape of the vocal tract, that is,a length of the oral cavity, a narrowing point in the vocal tract, adegree of opening of the vocal tract, and the like. When a sound isgenerated while there is not a narrowing point in the middle of thevocal tract, a resonance frequency of the generated sound is similar toa case in which the vocal tract is a cylinder pipe having one closedend, and a wavelength of the lowest resonance wave is 4 times as long asthe length of vocal tract. Change in a shape of an oral cavity due tomovement of a tongue and a chin leads to a change in the length of thevocal tract. Among organs of speech, an articulatory organ includes apharynx, an esophagus, a uvula, a hard palate, a tongue, lips, etc. anda resonance organ includes sound-producing organs including the pharynx,oral cavity, and a nasal cavity. In general, a voice spectrum isrepresented as a spectrum of the vocal cord sound times frequencyresponse characteristics of the vocal tract. As such, since theresonance characteristics of the vocal tract work as a filter and thusthe harmonics are strengthened at some frequencies and weakened at otherfrequencies according to a size and a shape of the vocal tract, that is,a length of the oral cavity, a narrowing point in the vocal tract, adegree of opening of the vocal tract, and the like, characteristics ofvoice signals of people having different vocal cord structures may bevariously exhibited. Furthermore, similar to humans, pets or wildanimals also have the difference between characteristics of voicesignals due to the difference between vocal cord structures. The vehicle100 according to an embodiment of the present invention may generate andoutput a unique and distinctive driving sound of the vehicle 100 desiredby the driver 106 in consideration of characteristics of a unique voicesignal of a human, pet, or wild animal, thus satisfying a requirement ofthe driver 106.

The filter generation unit 210 is used to extract a characteristic of avoice signal to generate a driving sound filter considering thecharacteristic of the voice signal. To this, the filter generation unit210 includes a filter synthesis unit 204 and a filter storage unit 206.The filter synthesis unit 204 is used to perform spectral analysis on avoice signal (for example, a voice of driver 106) received through themicrophone 202 and select at least one main resonance frequency of thevoice signal. In order to more accurately extract the characteristic ofthe voice signal, the filter synthesis unit 204 may select more mainresonance frequencies. As such, the filter synthesis unit 204 mayextract the main characteristic of the voice signal through the spectralanalysis and the selection of the main resonance frequency. The filtersynthesis unit 204 may generate a driving sound filter considering thecharacteristic of the voice signal when the selected main resonancefrequency is used. The driving sound filter may be a finite impulseresponse (FIR) filter. The driving sound filter may be an infiniteimpulse response (IIR) filter. The filter storage unit 206 is used tostore a completed driving sound filter. A driving sound filter stored inthe filter storage unit 206 may adjust a level of a target driving soundby adjusting an amplitude (in decibels) of a resonance frequency.

The driving sound control unit 110 generates a default driving soundbased on a driving state of a vehicle and generates a new driving soundin which the driving sound filter is applied to the default drivingsound. To this, the driving sound control unit 110 includes a drivingstate detection unit 218 and a control unit 212. The driving soundcontrol unit 110 may further include a speaker 214. The driving statedetection unit 218 acquires driving state information of the vehicle 100and provides the acquired driving state information to the control unit212. The driving state detection unit 218 will be described in detailbelow with reference to FIG. 3. The control unit 212 generates a defaultdriving sound considering a driving state of the running vehicle 100 onthe basis of driving state information of the vehicle 100 that isprovided from the driving state detection unit 218. Here, the defaultdriving sound may be selected from among a plurality of default drivingsounds that are previously provided in consideration of various drivingstates of the vehicle 100. Alternatively, the default driving sound maybe generated in consideration of the current driving state of thevehicle 100 in real time. The control unit 212 passes the defaultdriving sound to a driving sound filter of the filter storage unit 206to generate a new driving sound by applying a characteristic of thedriving sound filter to the default driving sound. An example of thecontrol unit is an electronic control unit (ECU) for electronicallycontrolling the vehicle 100.

The speaker 214 is used to output a new driving sound generated by thedriving sound control unit 110, and may be, for example, an audio deviceprovided in the vehicle 100 or a speaker provided in a multimediadevice, a navigation device, and the like.

FIG. 3 is a block diagram showing a configuration of a driving statedetection unit as shown in FIG. 2. As shown in FIG. 3, the driving statedetection unit 218 may include a revolutions-per-minute (RPM) sensor302, a torque sensor 304, a throttle position sensor 306, an acceleratorposition sensor 308, and a wheel speed sensor 310.

The RPM sensor 302 is a sensor used to detect revolutions per minute(RPM) of the engine 102 and generates a corresponding number of pulsesto the number of cylinders of the engine 102 per one revolution. Forexample, the RPM sensor 302 generates four pulses per one revolution fora four-cylinder engine, six pulses per one revolution for a six-cylinderengine, and three pulses per one revolution for a three-cylinder engine.The control unit 212 determines the number of revolutions of the engine102 by using the number of pulses per minute that are generated by theRPM sensor 302.

The torque sensor 304 is a sensor used to detect a torque of the engine102. The control unit 212 may determine a degree of load of the engine102 through the torque sensor 304.

The throttle position sensor 306 is a sensor used to detect a positionof a throttle valve according to an operation (acceleration) of anaccelerator pedal by a driver. The throttle position sensor 306 is avariable resistor element that rotates with a throttle shaft of athrottle body, and detects the position of the throttle valve. Aresistance of the throttle position sensor 306 varies depending on therotation of the throttle valve and thus an output voltage of thethrottle position sensor 306 changes. The control unit 212 determinesthe position of the throttle valve through the change in the outputvoltage. The control unit 212 determines an operation mode of the engine102 from information such as the output voltage (that is, the positionof the throttle valve) and an engine rotation number. Furthermore, thecontrol unit 212 may allow a vehicle driving sound appropriate for anoperation mode of the engine 102 to be generated by determining adriving control value of a vibration generator 214 according to theposition of the throttle valve,

The accelerator position sensor 308 is a sensor used to detect an amountof operation of the accelerator pedal. That is, if the amount is set as0% when the driver 106 does not press the accelerator pedal, and set as100% when the driver 106 presses the accelerator pedal to the floor, theaccelerator pedal sensor recognizes the amount of operation of theaccelerator pedal by the driver 106 as a value between 0% and 100%. Theaccelerator position sensor 308 is a set of two sensors: one is used todetect the amount of operation of the accelerator pedal, and the otheris used to detect (monitor) a failure.

The wheel speed sensor 310 is a sensor used to detect a speed ofrevolutions of a wheel of the vehicle 100.

The control unit 212 receives detection values from the RPM sensor 302,the torque sensor 304, the throttle position sensor 306, the acceleratorposition sensor 308, and the wheel speed sensor 310 included in thedriving state detection unit 218 and controls running of the vehicle100. The driving state detection unit 218 may further include anothersensor in addition to the RPM sensor 302, the torque sensor 304, thethrottle position sensor 306, the accelerator position sensor 308, andthe wheel speed sensor 310. In addition, the control unit 212 generatesa default driving sound considering a current driving state of thevehicle 100 on the basis of the driving state information of the vehicle100. A new driving sound is generated by passing the default drivingsound to the driving sound filter according to an embodiment of thepresent invention before the default driving sound is output through thespeaker 214, and then output through the speaker 214.

FIG. 4 is a flowchart showing a method of generating a driving soundfilter in controlling a driving sound of a vehicle according to anembodiment of the present invention. As shown in FIG. 4, the methodincludes first receiving a voice signal through a microphone 202 that isa voice signal input unit in order to generate a driving sound filterconsidering a characteristic of the voice signal (402). The voice signalis a voice of a driver 106 or someone else or a cry of a pet or wildanimal. When the voice signal is received, a filter synthesis unit 204performs spectral analysis on the received voice signal (404). Thefilter synthesis unit 204 selects at least one main resonance frequencyof the voice signal from a result of the spectral analysis performed onthe received voice signal (406). In order to generate a driving soundfilter having a better quality, it is preferable to select more mainresonance frequencies. It will be described in detail below withreference to FIG. 5. When at least one main resonance frequency isselected, the filter synthesis unit 204 calculates an energy level ofthe selected main resonance frequency (408). The filter synthesis unit204 uses the selected main resonance frequency to generate a drivingsound filter considering the characteristic of the voice signal andstores the main driving sound filter in the filter storage unit 206(410). As such, the driving sound filter stored in the filter storageunit 206 is provided to the driving sound control unit 110 and used togenerate a driving sound desired by the driver 106 when the driver 106desires the new driving sound considering the characteristic of thevoice signal while the vehicle 100 is running.

FIGS. 5A and 5B are views showing selection of a main resonancefrequency and generation of a filter through spectral analysis. First,FIG. 5A shows a spectrum of the received voice signal. In FIG. 5A, ahorizontal axis indicates time, a vertical axis indicates frequency, andbrightness of shadow indicates an energy level. The energy level ishigher as the shaded area is brighter, and the energy level is lower asthe shaded area is darker. As seen from FIG. 5A, the energy level aroundabout 525 Hz is about 12 dB, which is the highest level. In addition,the energy levels around about 310 Hz and about 1250 Hz are about 6 dB,which is the second highest level. As the result of the spectralanalysis, a driving sound filter having a characteristic as shown inFIG. 5B may be generated by selecting 525 Hz, 310 Hz, and 1250 Hz as themain resonance frequencies and then combining the frequencies. It can beseen through the characteristic of the driving sound filter of FIG. 5Bthat 525 Hz, 310 Hz, and 1250 Hz are the main resonance frequencies.

As such, the number and bands of main resonance frequencies may varydepending on a vocal cord structure of a provider of the voice signal.For example, voice signals of humans and animals have respectivedifferent unique characteristics because of a difference between vocalcord structures of humans and animals, and the difference may beacquired through spectral analysis of the voice signals.

As shown in FIGS. 4, 5A and 5B, when the driving sound filter iscompletely generated and stored, the driving sound control unit 110 maybe operated by selection of the driver 106 during actual running of thevehicle 100 to generate a new driving sound to which the driving soundfilter has been applied. FIG. 6 is a flowchart showing a method ofcontrolling a driving sound of a vehicle according to an embodiment ofthe present invention. The driving sound control unit 110 of the vehicle100 may be operated to output a driving sound desired by the driver 106in response to an operation of the driver 106 according to an embodimentof the present invention.

As shown in FIG. 6, when an operation of the driver 106 occurs in orderto output the driving sound desired by the driver 106, the control unit212 of the driving sound control unit 110 receives driving stateinformation of the vehicle 100 from the driving state detection unit 218(602). The control unit 212 receives default driving sound informationcorresponding to the current driving state of the vehicle 100 from thedriving state information of the vehicle 100 (604). The control unit 212combines the default driving sound according to the acquired defaultdriving sound information with a driving sound filter stored in thefilter storage unit 206 (606). That is, a new driving sound may begenerated by passing the default driving sound through the driving soundfilter to combine a characteristic of the driving sound filter with thedefault driving sound. When the new driving sound is generated, thegenerated driving sound may be output through a speaker, thus allowingthe driver 106 of the passenger compartment 104 to listen to the newdriving sound output through a speaker.

FIG. 7 is a view showing a method of generating a new driving sound bycombining a default driving sound of a vehicle and a driving soundfilter according to an embodiment of the present invention. In FIG. 7, awave form designated by reference numeral 704 indicates a characteristicof a default driving sound considering a driving state of the vehicle100, and a wave form designated by reference number 706 indicates aresult obtained by passing the default driving sound 704 through thedriving sound filter 702, that is, a new driving sound.

To provide a detailed description of FIG. 7 with reference to theabove-described FIG. 2, when the vehicle 100 is running with a drivingsound filter being stored in the filter storage unit 206, the controlunit 212 generates the default driving sound 704 considering a drivingstate of the vehicle 100 on the basis of the driving state informationof the vehicle 100 that is detected by the driving state detection unit218. In this case, the control unit 212 does not output the defaultdriving sound without any processing thereof, passes the default drivingsound through the driving sound filter previously stored in the filterstorage unit 206 to allow the default driving sound to reflect a uniquecharacteristic of the driving sound filter, and then outputs the defaultdriving sound considering the unique characteristic, thus allowing a newdriving sound having a characteristic desired by the driver 106 to begenerated and output.

As such, when the driver 106 is not satisfied with the default drivingsound considering the driving state of the vehicle 100, the driver 106can add his/her voice, someone's voice, a cry of a pet of the driver106, or a cry of a wild animal preferred by the driver 106 to thedriving sound of the vehicle 100, thus significantly increasingsatisfaction during running of the vehicle 100.

According to an aspect, it is possible to significantly increasesatisfaction of a driver during running of a vehicle by providing adriving sound of the vehicle having a characteristic desired by thedriver.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

What is claimed is:
 1. A vehicle comprising: a voice signal input unitconfigured to receive a voice signal; a filter generation unitconfigured to extract a characteristic of the voice signal and generatea driving sound filter considering the characteristic of the voicesignal; and a driving sound control unit configured to generate adefault driving sound based on a driving state of the vehicle andgenerate a new driving sound obtained by applying the driving soundfilter to the default driving sound.